


Knowledge is power

by SeparationBoundary



Category: Shingeki no Kyojin | Attack on Titan
Genre: Aged-Up Character(s), Anal, Bottom!Jean, Fingering, First Time Bottoming, Levi's a goooood teacher, M/M, Multi, Plot What Plot/Porn Without Plot, Threesome - M/M/M, Top!Levi, bottom!Eren
Language: English
Status: Completed
Published: 2017-07-23
Updated: 2017-07-23
Packaged: 2018-12-06 03:14:11
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,170
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11591760
Author URL: https://archiveofourown.org/users/SeparationBoundary/pseuds/SeparationBoundary
Summary: Eren and Jean explore their feelings, then Levi shows up.What can they learn from a mentor?A dark and sexy mentor.





	Knowledge is power

**Author's Note:**

> As always, any minor characters are aged up to legal, thus Eren is 21 and Jean,22. Levi's sexy self is canon age.

“C’mon loser! Show me what you got!”  
Jean backed away slowly, his lanky body all long legs and a devilish grin.  
Eren stalked toward him.

The two were alone in the compound. Hange was somewhere doing something but they might not see her for days at a time. Commander Erwin and Captain Levi were gone on business and Moblit had the rest of the recruits out felling trees and chopping wood.

They both were supposed to be resting. Eren, after a strenuous session of transforming for Hange, and Jean, due to a sprained ankle.  
So of course they had immediately gone out into the compound and started sparring.  
What had begun as an innocent practice, though, had devolved into an almost completely serious battle. Both boys had shed their shirts and were dripping with sweat.  
“Stand still, damn you,” Eren growled, feinting at the taller boy.  
Jean laughed and skipped away, favoring his left leg, but getting clear anyway. Eren was weak from the experiments.  
“Big, bad, shifter guy,” Jean cooed, “Come get me!”  
Eren watched Jean slip sideways, always to the left, pushing off with his good leg. The next time Eren came at him, Eren dodged left, then right, catching Jean around the waist and slinging him to the ground. Jean grappled with him, dragging the brunette down on top of himself. They rolled in the dust, trying to get a good grip on each other’s sweat slick skin.  
They ended up off to one side, where the shadow from the building made a blessedly cool, dark spot. They lay gasping, finally, tangled together, both too tired to fight any more.  
Jean lay spread eagle on his back, Eren on top of him, his dark head on the taller boy’s shoulder.  
It didn't take Jean a moment to notice the embarrassingly intimate pose.  
“Hey, get offa me, you weirdo.” he pushed at Eren’s shoulder. “What are you? Some kinda pervert.”  
“Tired,” Eren mumbled.  
“Yeah, well, be tired somewhere offa me.”  
Jean tried to roll Eren off but the kid was fucking heavy. He suddenly went very still and a blush crept up his face.  
Eren lifted his head slowly and looked Jean in the face. Jean went crimson.  
“Are you …” Eren said quietly, “Are you hard?”  
Jean opened his mouth but couldn’t speak. He covered his face with his free hand.  
“Shit!”  
Eren reached up and pulled at his fingers.  
“Shit, shit, shit! Leave me alone!” Jean said.  
Eren pried at his fingers, lifting his hand off, finally.  
They stared at each other a moment.  
Eren ducked his head and kissed Jean on the mouth. It was a quick, chaste kiss and Jean just gaped up at him.  
“Wh - What? …”  
Eren took advantage of Jean’s open mouth, kissing him again, deeper, tongue exploring.  
For a second Jean responded, arching slightly and letting out the tiniest of moans, then he pushed Eren’s face away, turning his head.  
“Maria, Eren! We’re both guys, man!”  
“Yeah,” Eren murmured “And Reiner and Bertholdt are guys.”  
Jean squeezed his eyes shut.  
“And Marco was a guy …”  
Jean’s head snapped around.  
“D-don’t you dare! Don’t you dare c-compare yourself …” he sobbed.  
Eren gently took Jean’s chin in his hand.  
“Jean. Marco is gone, but I’m here. You don’t have to be lonely. You’re making yourself miserable, keeping to yourself.”  
The tall cadet was quiet for so long that Eren was concerned. Then he smiled a tiny crooked smile.  
“I suppose Armin came up with this brilliant deduction?”  
Eren grinned. It was his simple, open, Eren smile and Jean just had to soften at the sight of it.  
“As a matter of fact, Armin was planning on doing this himself.”  
Jean’s eyes widened and Eren leaned down, kissing him again.  
The taller boy responded this time, freeing his other hand and wrapping both arms around the other cadet. Eren hummed and ground his own erection against Jean’s, making him moan.  
Eren pulled back, desperately fumbling with Jean’s trousers with one hand and his own with the other. Jean stared up at him, mouth open, eyes glazed with lust. Eren freed his own cock and fell on Jean’s as it sprang out. Eren took them both in hand, pressing his length against the other cadet’s, stroking both.  
Jean groaned and threw his head back, fingers clutching Eren’s arms.  
Eren slowly stroked both hard-ons, loving the way Jean squirmed and gasped as he did.

What he didn't know was that they were being watched.

Levi, Captain of the survey squads and a bit over ten years their senior, had come back early, to prepare some documents and had come out into the compound to find the two cadets. He knew them well enough to know that they’d be out doing something stupid instead of resting.

He hadn't expected this.

He calmly and quietly watched the two young men. They were both handsome specimens and their cocks were gorgeous. Also, at 21 and 22, it didn’t take much to get them off. In just a few moments Jean arched up and came and Eren quickly finished.  
“Maria! You’re an idiot Yeager! You came all over me!”  
“You came all over yourself first.”  
For a moment the two looked like they were going to fight, again, but then both boys burst into laughter. Eren was helping Jean up when Levi sank back around the corner of the mess hall.  
He leaned casually against the wall, deep in the shadow, arms crossed. He could hear their voices getting closer.  
“Jeez, what a mess,” that was Jean.  
“At least tuck your shirt in,”  
They both rounded the corner into the chunk of shade where Levi stood. Abruptly Eren leaned into the taller cadet and kissed him. Levi could see Jean blush from where he was and return the kiss shyly. They separated.  
“I’m glad we decided to spar,” Eren murmured in a voice that went straight to Levi’s groin.  
Jean rubbed the back of his head and grinned at the ground.  
“Yeah, yeah … that was … we should do that again.”  
Eren smiled and turned and looked up. Straight at the Captain.  
The brunette choked on his own spit and froze.  
“The hell?” Jean’s gaze followed Eren’s and he looked exactly like a deer in torchlight; still, open mouthed, wide eyed.  
“Heichou …” Eren whispered. “How … how long have you …?”  
“The whole time.”  
Levi didn’t stir, enjoying the two sweating.  
Jean put up both hands, palms out.  
“It w-wasn’t what it looked like!”  
Levi pushed himself away from the wall.  
“Of course it was.”  
Jean looked desperately at Eren who had a dreamy look on his face.  
“You … you watched us, Heichou?”  
The corners of Levi’s mouth tipped up slightly.  
“Yes. And that was the most inept hand job I’ve ever seen.” He turned and walked off into the sunshine, toward the big doors to the mess hall. He glanced over his shoulder.  
“If you two want to learn how it’s really done, come see me tonight.”  
\---

Eren was having to almost drag Jean.  
“This is a bad idea, dude!”  
“It’s not, Jean. Think of how much we can learn.”  
“Think of that scary fucker tying us up and hurting us!”  
Eren stopped.  
“Oh, come on. Captain wouldn’t hurt us! He’s not gonna tie us up!”  
“Remember that time he kicked the shit out of you?!”  
“Ugh! That was just for show, so I could be here!”  
Eren coaxed Jean into walking again.  
“Umm, I wonder what Heichou’s hands feel like?” Eren murmured.  
“See,” Jean said, “You’ve been sweet on him for a while but I-”  
They had arrived at Levi’s office, adjacent to which was Levi’s bedroom.  
Eren’s mouth was suddenly dry  
That didn’t stop him from knocking, though.  
“Come.” Levi’s voice said.  
Eren actually shivered at the unintentional double entendre.  
He took the knob firmly in one hand and Jean firmly in the other and opened the door.

Levi sat behind his desk and didn’t bother to look up. There were two candles guttering low on his desk, one on either side of him. He was working on paperwork.

“Captain,” Eren said quietly.  
“Y-you look busy,” Jean stuttered, “We can come back lat-”  
Eren punched him hard on the shoulder.  
“Ow!”  
Levi began gathering his papers, filing them away, wiping off his quills, closing his ink.  
When he was done, he laced his fingers and looked up at them.  
“Kirstein!”  
Jean jumped. “S-sir?”  
“What you and Eren did today. Did you enjoy it?”  
Jean went red. He fiddled a bit with his shirt buttons and shuffled his feet. Eren began to get worried that his friend hadn't really enjoyed it.  
“Ye-es, Sir.” Jean finally admitted. “Yeah.”  
“Do you want to learn how to do more?”  
Both cadets blushed.  
Eren couldn’t help himself,  
“Will you teach us, Captain?”  
Levi stood then, pausing just a second to show off his hard, lean physique.  
“Of course” He grew serious, “Only if you want.”  
Eren nodded eagerly as if he’d been offered candy. Jean nodded more slowly.  
“Y-you're not gonna tie us up are you?” Jean blurted.  
“Only if you want,” Levi repeated, leveling a completely serious look at the squirming cadet.  
\---  
Levi eased around the desk until he was in front of the two cadets. He leaned back against the wood.  
“Eren,” he said.  
Eren jumped, “S-sir?”  
“Kiss Jean, would you?”  
“Uh …”  
Levi frowned at the two cadets.  
“Well, we’re not here to dance, are we?”  
Eren chuckled sheepishly.  
He turned to the other boy who was clearly nervous and uncertain. Eren slipped an arm around the taller cadet’s waist and ran his other hand around the back of his neck, tickling the short hairs there.  
“Relax, Jean. It felt good before, right?”  
Jean nodded, half eager, half scared.  
Eren leaned up and kissed him. After a moment Jean began to uncoil, his arms went around Eren and he responded to the kiss.  
They lost track of where they were, what they were doing, and just kissed.  
Suddenly there was a firm, warm body beside them, close enough to touch. It was levi. He snaked an arm around the back of each cadet’s neck, resting his hands on their napes.  
They broke off their kiss and stared at him.  
He dragged Eren down to his mouth first, claiming him fully, licking deep into his mouth. Eren couldn’t contain a moan of pleasure.  
Jean was already leaning down when Levi broke off from Eren. Their kiss was wilder, deeper, more dangerous. Jean grunted in pleasure, tentatively running his hands over his superior’s beautiful body.  
Levi arched up, taking in every stroke of Jean’s hands. He wound both arms around the tall cadet’s neck and Eren whined in displeasure.  
Levi kissed Jean thoroughly and then turned to Eren, claiming his mouth as jean kissed and sucked along Levi’s neck.  
Levi was fully, painfully, hard and he grasped both boys by the hair, sandy blond in one hand, chestnut in the other.  
The two young men stilled, afraid, and incredibly turned on.  
Levi slowly and purposely pushed downward.  
Abruptly both boys were presented with their superiors hot, straining, erection.  
Levi’s cock was fucking gorgeous. It was impressively long and thick and the fat throbbing veins that traced it were exquisite.  
Eren's gaze met Jeans across the blushed red head of Levi’s cock which leaked pre-cum.  
“W-wha …?”  
Eren, however, had a great imagination and impressive determination. He licked tentatively up his side of heichou's cock.  
Jean stared openmouthed.  
Eren moaned and licked again, firmer and more decisively up Levi’s beautiful cock and tongued at the slit.  
Levi arched up, groaning.  
Jean suddenly realised that he wanted this prize, too, and tentatively licked up the other side of Levi’s erection until his spit dripped down the captain’s cock.  
The two cadets instantly made a competition of it and Levi had to bite his lip to keep back his sounds of pleasure.  
The two boys licked and sucked and swirled their tongues pausing every now and then to kiss each other in a leisurely manner. They alternated taking as much of heichou as they could. Levi was barely keeping it together. His hands in their hair trembled, his legs shook.  
“Nnngh! Ahh! OK, that’s enough.”  
Levi pulled them off his dick with difficulty.  
“Kirstein,” Levi growled. “Bed. Now.”  
The gawky cadet retreated to the bedroom, shedding clothes as he went.  
Levi kissed Eren again, left bite marks on his neck.  
“You, too Yeager.”  
The boy disappeared and Levi paced as slowly and maturely as he could to his own bed, his rock hard erection bobbing in front of him.

Jean and Eren were locked in a kiss and squirming around on the bed, giggling and trying to get the rest of each other’s clothes off. Levi actually smiled a tiny smile at their youthful antics.  
Both were basically naked, Eren on all fours over Jean, when Levi knelt on the edge of the bed. He crawled slowly and somehow dangerously to them.  
Both cadets tried to grab his cock but he slapped them away. He reached for the bedside table, pulling the drawer out and snagging a small bottle.  
He held the two young men in place and positioned himself behind Eren, straddling Jean’s legs.  
“Do you know how this works?” He murmured. A shudder ran through both boys simultaneously. “Fucking a man?”  
They both spoke at the same time, too.  
“Well … uh … I mean …”  
“It’s pretty obvious something has got to go in …”  
Levi sighed.  
“OK, watch and listen, brats”  
He gently pushed Eren aside and stretched out over Jean. The cadet was very tall and Levi couldn’t kiss him and grind his cock against Jean’s cock at the same time. He contented himself with a kiss then slid down between the young man’s legs. He loosely grasped Jean’s cock. Jean gasped and Eren moaned, handling his own dick.  
Levi fell on the boy’s nipples, licking and sucking and his free hand snaked up under Jean’s balls.  
The boy arched off the bed as Levi bit his nipples and sent a well lubed finger around his asshole.  
Jean’ ass spasmed and Levi slid one finger in.  
“AHHH! That … that feels …”  
Eren was instantly beside his friend, kissing him, soothing him.  
Levi determinedly eased another finger in. Jean’s lashes were beaded with tears now and he arched and squirmed and moaned.  
“Does it feel good, Jean?” Eren whispered, “Fingers up your ass? Does it hurt a lot?”  
“I-it hurts a little - AH! - stretches. B-but it feels good!”  
Levi reared back, off of Jean, and pulled Eren by his hips to resume his on all fours pose over the other cadet.  
“Eren, Jean, stroke each other,” Levi murmured.  
They didn’t need any encouragement, but slowly jerked each other.  
Eren felt a cold slick finger at his ass. Before he could really protest, Levi had a finger in him and two in Jean. He fucked them slowly and in rhythm. Their moans soon matched.  
After an agonisingly slow ten minutes, Levi had three fingers in both cadets. Both were coming undone under his ministrations  
“Eren,” Levi murmured.  
The chestnut haired boy looked back at him and in his eyes was half apprehension and half unbridled lust.  
Levi suddenly withdrew his fingers from both cadets, earning him two protesting whines.  
The captain reached around and gripped Eren's dick. The boy hissed in a breath.  
Levi’s other hand appeared with the lube.  
Soon Eren’s cock was glistening with lube and he was groaning as Levi slowly stroked him. Below him, Jean writhed in frustration.  
“Nnnh … guys … please?”  
“Down,” Levi said to Eren “go down, flatter,”  
Eren did and Levi abruptly grabbed both of Jean’s long legs and lifted, pushing his knees toward his shoulders.  
Eren looked down, down at Jean’s throbbing erection, at his newly exposed and glistening asshole.  
He finally caught on.  
“Hey!” Jean said, “Captain? What are you … Ahhhhh! AHH! Eh-her-EN!”  
Eren stopped completely with just the head in his friend’s twitching hole.  
“Does it hurt? Too fast?” Eren searched Jean’s face.  
“Just fucking … move, you bastard!”  
Eren grinned and began fucking into the other cadet.  
“Go slow,” Levi murmured from behind him, “Take it easy.”  
Eren established a slow rhythm, introducing his hard member an inch at a time.  
Levi, meanwhile, was licking and biting over Eren’s back.  
Inspired, Eren dropped his head to suck at Jean’s neck.  
Very soon, Eren had his entire length in Jean. He paused to let the other adjust, lying flat on the other boy, kissing over his collarbone.  
“Does it feel good?”  
“It feels fucking amazing,” Jean murmured, one arm thrown over his face. “Why don’t you get back to work idiot,” he lifted his arm so he could glare at Eren, “And fuck me?!”  
Eren grinned again but before he could move he felt hands on his hips.  
“Steady Yeager,”  
He felt something at his entrance. It pressed insistently in.  
“Captain, Levi! I … UHH!”  
Eren could swear he saw stars. The effect was intense, Jean’s ass gripping his cock, Levi’s cock pressing into his own ass.  
Tears beaded on his lashes and dripped onto Jean’s neck.  
“Hey, hey, Eren,” Jean said, “You OK?”  
“God, Captain is so big!” Eren breathed.  
Levi didn’t pause or retreat, he just slowly slowly fed his cock into Eren’s ass.  
“Haah! Nnn!”  
Eren groaned and gasped.  
Levi leaned over him, nibbling at his back.  
“Does that feel good? Do you enjoy my fat cock in your ass?”  
“Ahh, god, yes! Captain, y-yes!”  
“Naughty boy. Both of you are such naughty brats,” Levi murmured.  
Abruptly Levi straightened and grabbed Eren’s hips hard enough to bruise. He began fucking him with determination, slower at first then faster, harder. His action pushed Eren into Jean exactly as fast and as hard.  
The two young men were overwhelmed at the sensation, neither could speak, they both just rapidly came undone under Levi.  
“You eager things,” Levi murmured, “Those tight assholes just begging for cock. You dirty boys.”  
“God …” Jean groaned, “Y-you're gonna make me cum c-captain, just from t-talking.”  
Levi hummed, shoving himself into Eren,  
“Do it. There’s a filthy brat. Come for Levi.”  
Jean came then, arching up off the bed, enough to lift Eren and Levi, his cum smearing hot and thick between his and Eren’s bellies.  
“Ahhh, hah! C-captain. Can I cum too, please?”  
Levi hadn't altered his punishing pace, fucking into eren.  
“Of course. Are you a naughty boy too?”  
“Yes, yes, YES! I’m bad, Heichou. So bad!”  
“And that's why Levi has to punish you,” Levi whispered.  
He focussed on fucking the cadet and Eren’s moans turned into shrieks.  
“P-please Heichou!”  
“You can cum, Eren. I’l finish punishing you dirty boys later.”  
Eren twitched and gasped and came inside Jean. he fell down on the taller boy’s chest and Levi leaned forward, bracing himself on Eren’s shoulders.  
“HAH! Ahhhh!” Levi was trembling, cumming, “Oh fuck yeah! Nnnngh! Such filthy brats!”  
Levi finally rode his orgasm out. He laid his cheek on eren’s back  
“So, so bad.” He sighed

**Author's Note:**

> As always, thank you so much for reading!  
> If you enjoyed this story please leave kudos, and if you have anything kind or helpful to say, please leave a comment!


End file.
